Query to find duplicates owned by both SYS and SYSTEM

 SELECT object_name, object_type
     FROM dba_objects
     WHERE object_name||'_'||object_type IN
     (SELECT object_name||'_'||object_type
       FROM dba_objects WHERE owner = 'SYS')
       AND owner = 'SYSTEM' AND object_name NOT IN ('AQ$_SCHEDULES',
       'AQ$_SCHEDULES_PRIMARY','DBMS_REPCAT_AUTH','DBMS_REPCAT_AUTH');